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Black Aluminium Windows


Klosen / Aluminium Windows / Black Aluminium Windows

Cortizo Flush Casement Windows
New upstairs window in an old brick wall
Heritage Windows


Want only the most modern, stylish and durable windows for your home? Our exciting lineup of double and triple-glazed black aluminium windows are exactly what you’ve been searching for.

Here at Klosen, we provide a complete start to finish service. From supplying, installing and maintaining them, we do it all for homeowners and businesses in Peterborough and beyond.

We’re so confident in the quality of the products we supply and the integrity of our installations that we offer a 10-year warranty on all our aluminium windows and doors – giving you total peace of mind.

To find out more, download a brochure or request your free quotation.

Why Choose Black Aluminium Windows?

The advantages of aluminium windows are significant.

  • They’re incredibly durable; aluminium doesn’t rust, rot or crack
  • They boast excellent thermal and sound insulation thanks to recent technological enhancements
  • Their increased strength allows for thinner frames, allowing more light into your home for an airy, spacious feel
  • They’re no more difficult to install than PVC or wood-framed ones
  • They look simply sensational – options are available to suit all kinds of homes, from historic to contemporary

They are available in a range of colours and finishes, but black has proven to be one of the most popular choices with our customers. Why? It looks the part, that’s for sure – on the right home or premises, black windows can contrast beautifully with brickwork, setting your property apart from those nearby.

Both modern and historic buildings can benefit from black aluminium windows – and they can transform any property from staid to striking. To help you get inspired, here are some installations we’ve recently completed…

Brands We Work With

New windows represent a significant investment for any property owner, so it’s vital that high-quality frames are fitted. It’s for this reason that we’re very selective about what we supply here at Klosen.

We only supply Cortizo and Senior Architectural Systems windows because we believe them to be the best in the business. Exquisitely engineered and designed to last, we’re confident that you’ll be thrilled with every aspect of their design – and our 10-year guarantee is testament to their strength and durability.

Learn more about each brand below, or download a brochure for further information.

Contact Us
Senior Architectural Systems Logo
Cortizo Logo

10 Year Guarantee

We offer a 10-year guarantee on all profiles and 25 years for the powder coating element

Thermal Efficiency

Stay warm in the winter and cool in the summer whilst cutting down on energy bills

Complete Flexibility

Our team are flexible throughout the entire process, including the design and installation of windows

25+ Years Experience

Klosen have over 25 years experience working with designers, architects and homeowners


Cortizo is one of the world’s most renowned manufacturers of aluminium windows and doors. Based in Spain, the company has led the industry for many years, constantly innovating and refining its impressive range of products.

Although they’re extremely well-built and boast exceptional efficiency, it’s the stunning design of Cortizo that really set them apart.

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Cortizo Specifications

Transmittance: Uw ≥ 1.0 (W/m2K)

Acoustic insulation: Rw up to 45 dB

Air permeability: Class 4

Water tightness: Class E1200

Wind resistance: Class CE 2400

Security test: PAS24 passed

Our Customer Reviews

Great Price & Quick Delivery

This company have been amazing and came to our rescue when another company let us down repeatedly over a period of 4 months during our building work. We got a great price, a quick delivery time and the same product but this time with lovely fitters who knew exactly what they were doing. Now we will will have a warm house for christmas HOORAY !! We went for 3 large sliding doors and the quality of the product is excellent . Many thanks to Audrey Cieran and the team I would recommend highly
- Esther Young


Delighted with the product and the service provided by Klosen. The installation team were excellent and very helpful.
- Sara Hyem

Very Happy

We’ve been very happy with the work Klosen recently completed for us. They installed a variety of windows and sliding doors for us on our new build project. All of the information we requested early on was provided promptly and they were great with our architect. Very happy with the end result and the colour they helped us chose.
- Sarah Munton

Senior Architectural Systems

Senior Architectural Systems is a British company with a history dating back over 30 years, making it one of the nation’s leading suppliers of aluminium windows and doors.

Located in Doncaster, the company is one of the most innovative and forward-thinking around; it was the first to incorporate a polyurethane foam thermal barrier into its designs and the first to offer powder coated finishes with a no-quibble guarantee.

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modern house with glass and wood panels

Senior Architectural Systems Specifications

Typical sizes:
Width (mm)

Height (mm)
x 1500

Thickness 28mm – 50mm

Air Permeability: 600 Pa
Water Tightness: 600 Pa
Wind Resistance: 2400 Pa

Residential CEN Standard:
1230 x 1480 28mm Double Glazed Unit: 1.24 W/m2K

Tested to PAS24, BS6375-2 and BS6375-3

Typical sizes:
Width (mm)

Height (mm)
x 1400

Thickness 28mm – 44mm

Air Permeability: 600 Pa
Water Tightness: 600 Pa
Wind Resistance: 1600 Pa

Residential CEN Standard:
1230 x 1480 28mm Double Glazed Unit: 1.40 W/m2K

Tested to PAS24, BS6375-1, BS6375-2 and BS6375-3


As one of Cambridgeshire and London’s premier suppliers of black aluminium windows, we’ve worked on a whole host of exciting projects over the years. One of the stand-outs was this stunning dream home, as featured on Grand Designs in 2021.

We were approached by the owners to install a number of Cortizo designs and were delighted by the end result – as were they! We’ve been involved with a number of other high-profile projects too – why not take a look?

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Areas We Cover

Based in Market Deeping, Lincolnshire, we cover towns and cities within a 60-mile radius, including the entirety of Cambridgeshire and Lincolnshire. Areas we regularly visit include Peterborough, Bourne, Stamford, Huntingdon and London.

Why Choose Klosen?

  • Over 25 years of experience
  • Five-star reputation
  • 10 year guarantee on all work as standard
  • No project is too big or small
  • Experience working on high-profile projects, including a Grand Designs home and the ABBA Arena in London

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Are black aluminium windows right for my property?

Struggling to decide whether or not black is the right colour choice for your home or business premises? Our windows are available in hundreds of alternative RAL colours, so there’s bound to be one that you fall in love with.

How much do your aluminium windows cost?

Every installation is a little different, so we can’t list approximate prices. Happily, it’s very easy to get a quote on our website, or you can pick up the phone and call us if you prefer.

How long are lead times for a window installation?

On average, our lead times are currently five to six weeks from initial enquiry to installation.

Get in touch with us today to receive your free quotation!